/******************************************************************
 *****                                                        *****
 *****  Name: tcpip.h                                         *****
 *****  Ver.: 1.0                                             *****
 *****  Date: 07/05/2001                                      *****
 *****  Auth: Andreas Dannenberg                              *****
 *****        HTWK Leipzig                                    *****
 *****        university of applied sciences                  *****
 *****        Germany                                         *****
 *****  Func: header-file for tcpip.c                         *****
 *****                                                        *****
 ******************************************************************/

#ifndef __TCPIP_H
#define __TCPIP_H

// stack definitions
//#define MYIP_1               192                 // our internet protocol (IP) address
//#define MYIP_2               168
//#define MYIP_3               1
//#define MYIP_4               244
//const unsigned short MyIP[2] =                    // "MYIP1.MYIP2.MYIP3.MYIP4"
//{
//  MYIP_1 + (MYIP_2 << 8),                        // use 'unsigned int' to
//  MYIP_3 + (MYIP_4 << 8)                         // achieve word alignment
//};

//#define SUBMASK_1            255                 // subnet mask
//#define SUBMASK_2            255
//#define SUBMASK_3            252
//#define SUBMASK_4            0
//const unsigned short SubnetMask[2] =              // "SUBMASK1.SUBMASK2.SUBMASK3.SUBMASK4"
//{
//  SUBMASK_1 + (SUBMASK_2 << 8),                  // use 'unsigned int' to
//  SUBMASK_3 + (SUBMASK_4 << 8)                   // achieve word alignment
//};

//#define GWIP_1               192                 // standard gateway (used if remote
//#define GWIP_2               168                 // IP is no part of our subnet)
//#define GWIP_3               1
//#define GWIP_4               1
//const unsigned short GatewayIP[2] =               // "GWIP1.GWIP2.GWIP3.GWIP4"
//{
//  GWIP_1 + (GWIP_2 << 8),                        // use 'unsigned int' to
//  GWIP_3 + (GWIP_4 << 8)                         // achieve word alignment
//};

#define RETRY_TIMEOUT        8                   // wait max. 8 x 262ms for an ACK (about 2 sec.)
#define FIN_TIMEOUT          2                   // max. time to wait for an ACK of a FIN
                                                 // before closing TCP state-machine (about 0.5 s)
#define MAX_RETRYS           1 //4               // nr. of resendings before reset conn.
                                                 // total nr. of transmissions = MAX_RETRYS + 1

#define MAX_TCP_DATA_SIZE    1450                 // chi user defined
#define MAX_TCP_TX_DATA_SIZE 1478                 // max. outgoing TCP data size (even!)
#define MAX_TCP_RX_DATA_SIZE 1478                 // max. incoming TCP data size (even!)
                                                 // (increasing the buffer-size dramatically
                                                 // increases the transfer-speed!)
                                        
#define MAX_ETH_TX_DATA_SIZE 84                  // 2nd buffer, used for ARP, ICMP, TCP (even!)
                                                 // enough to echo 32 byte via ICMP

#define MAX_UDP_TX_DATA_SIZE 1478                // max. outgoing UDP data size (even!)
#define MAX_UDP_RX_DATA_SIZE 1478                // max. incoming UDP data size (even!)

#define DEFAULT_TTL          128                 // Time To Live sent with packets

// Ethernet network layer definitions
#define ETH_DA_OFS           0                   // Destination MAC address (48 Bit)
#define ETH_SA_OFS           6                   // Source MAC address (48 Bit)
#define ETH_TYPE_OFS         12                  // Type field (16 Bit)
#define ETH_DATA_OFS         14                  // Frame Data
#define ETH_HEADER_SIZE      14

#define FRAME_ARP            0x0806              // frame types (stored in Type/Length field)
#define FRAME_IP             0x0800

// IPv4 layer definitions
#define IP_VER_IHL_TOS_OFS   ETH_DATA_OFS + 0    // Version, Header Length, Type of Service
#define IP_TOTAL_LENGTH_OFS  ETH_DATA_OFS + 2    // IP Frame's Total Length
#define IP_IDENT_OFS         ETH_DATA_OFS + 4    // Identifying Value
#define IP_FLAGS_FRAG_OFS    ETH_DATA_OFS + 6    // Flags and Fragment Offset
#define IP_TTL_PROT_OFS      ETH_DATA_OFS + 8    // Frame's Time to Live, Protocol
#define IP_HEAD_CHKSUM_OFS   ETH_DATA_OFS + 10   // IP Frame's Header Checksum
#define IP_SOURCE_OFS        ETH_DATA_OFS + 12   // Source Address (32 Bit)
#define IP_DESTINATION_OFS   ETH_DATA_OFS + 16   // Destination Address (32 Bit)
#define IP_DATA_OFS          ETH_DATA_OFS + 20   // Frame Data (if no options)
#define IP_HEADER_SIZE       20                  // w/o options

#define IP_VER_IHL           0x4500              // IPv4, Header Length = 5x32 bit
#define IP_TOS_D             0x0010              // TOS low delay
#define IP_TOS_T             0x0008              // TOS high throughput
#define IP_TOS_R             0x0004              // TOS high reliability

#define IP_FLAG_DONTFRAG     0x4000              // don't fragment IP frame
#define IP_FLAG_MOREFRAG     0x2000              // more fragments available
#define IP_FRAGOFS_MASK      0x1FFF              // indicates where this fragment belongs

#define PROT_ICMP            1                   // Internet Control Message Protocol
#define PROT_TCP             6                   // Transmission Control Protocol
#define PROT_UDP             17                  // User Datagram Protocol

// ARP definitions
#define ARP_HARDW_OFS        ETH_DATA_OFS + 0    // Hardware address type
#define ARP_PROT_OFS         ETH_DATA_OFS + 2    // Protocol
#define ARP_HLEN_PLEN_OFS    ETH_DATA_OFS + 4    // byte length of each hardw. / prot. address
#define ARP_OPCODE_OFS       ETH_DATA_OFS + 6    // Opcode
#define ARP_SENDER_HA_OFS    ETH_DATA_OFS + 8    // Hardw. address of sender of this packet
#define ARP_SENDER_IP_OFS    ETH_DATA_OFS + 14   // IP address of sender
#define ARP_TARGET_HA_OFS    ETH_DATA_OFS + 18   // Hardw. address of target of this packet
#define ARP_TARGET_IP_OFS    ETH_DATA_OFS + 24   // IP address of target
#define ARP_FRAME_SIZE       28

#define HARDW_ETH10          1                   // hardware-type 10Mbps Ethernet
#define IP_HLEN_PLEN         0x0604              // MAC = 6 byte long, IP = 4 byte long
#define OP_ARP_REQUEST       1                   // operations for ARP-frames
#define OP_ARP_ANSWER        2

// ICMP definitions
#define ICMP_TYPE_CODE_OFS   IP_DATA_OFS + 0     // type of message
#define ICMP_CHKSUM_OFS      IP_DATA_OFS + 2     // checksum of ICMP-message (16 bit)
#define ICMP_DATA_OFS        IP_DATA_OFS + 4
#define ICMP_HEADER_SIZE     4

#define ICMP_ECHO            8                   // message is an echo request
#define ICMP_ECHO_REPLY      0                   // message is an echo reply

// TCP layer definitions
#define TCP_SRCPORT_OFS      IP_DATA_OFS + 0     // Source Port (16 bit)
#define TCP_DESTPORT_OFS     IP_DATA_OFS + 2     // Destination Port (16 bit)
#define TCP_SEQNR_OFS        IP_DATA_OFS + 4     // Sequence Number (32 bit)
#define TCP_ACKNR_OFS        IP_DATA_OFS + 8     // Acknowledge Number (32 bit)
#define TCP_DATA_CODE_OFS    IP_DATA_OFS + 12    // Data Offset and Control Bits (16 bit)
#define TCP_WINDOW_OFS       IP_DATA_OFS + 14    // Window Size (16 bit)
#define TCP_CHKSUM_OFS       IP_DATA_OFS + 16    // Checksum Field (16 bit)
#define TCP_URGENT_OFS       IP_DATA_OFS + 18    // Urgent Pointer (16 bit)
#define TCP_DATA_OFS         IP_DATA_OFS + 20    // Frame Data (if no options)
#define TCP_HEADER_SIZE      20                  // size w/o options

#define DATA_OFS_MASK        0xF000              // number of 32 bit words in the TCP Header

//TCPCode
#define TCP_CODE_FIN         0x0001
#define TCP_CODE_SYN         0x0002
#define TCP_CODE_RST         0x0004
#define TCP_CODE_PSH         0x0008
#define TCP_CODE_ACK         0x0010
#define TCP_CODE_URG         0x0020

#define TCP_OPT_MSS          0x0204              // Type 2, Option Length 4 (Max. Segment Size)
#define TCP_OPT_MSS_SIZE     4

// define some TCP standard-ports, useful for testing...
#define TCP_PORT_ECHO        7                   // echo
#define TCP_PORT_DISCARD     9                   // discard
#define TCP_PORT_DAYTIME     13                  // daytime
#define TCP_PORT_QOTD        17                  // quote of the day
#define TCP_PORT_CHARGEN     19                  // character generator
#define TCP_PORT_HTTP        80                  // word wide web HTTP

// UDP layer definitions
#define UDP_SRCPORT_OFS      IP_DATA_OFS + 0     // Source Port (16 bit)
#define UDP_DESTPORT_OFS     IP_DATA_OFS + 2     // Destination Port (16 bit)
#define UDP_PACKLENG_OFS     IP_DATA_OFS + 4     // Sequence Number (32 bit)
#define UDP_CHKSUM_OFS       IP_DATA_OFS + 6     // Acknowledge Number (32 bit)
#define UDP_DATA_OFS         IP_DATA_OFS + 8     // Frame Data (if no options)
#define UDP_HEADER_SIZE      8

// macros
#define SWAPB(Word)          ((unsigned short)((Word) << 8) | ((Word) >> 8))
                                                 // convert little <-> big endian

// typedefs
typedef enum {                                   // states of the TCP-state machine
  CLOSED,                                        // according to RFC793
  LISTENING,
  SYN_SENT,
  SYN_RECD,
  ESTABLISHED,
  FIN_WAIT_1,
  FIN_WAIT_2,
  CLOSE_WAIT,
  CLOSING,
  LAST_ACK,
  TIME_WAIT
} TTCPStateMachine;

typedef enum {                                   // type of last frame sent. used
  ARP_REQUEST,                                   // for retransmissions
  TCP_SYN_FRAME,
  TCP_SYN_ACK_FRAME,
  TCP_FIN_FRAME,
  TCP_DATA_FRAME
} TLastFrameSent;

EXTERN unsigned char  MyMAC[6];
//EXTERN unsigned short MyIP[2];                 
//EXTERN unsigned short GatewayIP[2];  
//EXTERN unsigned short SubnetMask[2];

EXTERN unsigned short N_MyIP[NIP_NUM][2];                 
EXTERN unsigned short N_GatewayIP[NIP_NUM][2];  
EXTERN unsigned short N_SubnetMask[NIP_NUM][2];

// properties of the just received frame
EXTERN unsigned short RecdFrameLength;           // EMAC reported frame length
EXTERN unsigned short RecdFrameMAC[3];           // 48 bit MAC
EXTERN unsigned short RecdFrameIP[2];            // 32 bit IP
EXTERN unsigned short RecdIPFrameLength;         // 16 bit IP packet length
EXTERN unsigned short RecdDestMAC[3];            // 48 bit MAC

EXTERN unsigned short _TxFrame[(ETH_HEADER_SIZE + IP_HEADER_SIZE + TCP_HEADER_SIZE + MAX_TCP_TX_DATA_SIZE)/2];
#define TxFrame      ((unsigned char *)_TxFrame)
EXTERN unsigned short TxFrameSize; 

//TCPFlags
#define TCP_ACTIVE_OPEN                0x01      // shall initiate a connection
#define IP_ADDR_RESOLVED               0x02      // IP sucessfully resolved to MAC
#define TCP_TIMER_RUNNING              0x04
#define TIMER_TYPE_RETRY               0x08
#define TCP_CLOSE_REQUESTED            0x10

// prototypes
EXTERN unsigned short netc[3];
unsigned int IsBroadcast(void);
void DoNetworkStuff(void);
void net_TCP_PRO(int);

// Handlers for incoming frames
void ProcessEthBroadcastFrame(void);
void ProcessEthIAFrame(void);
void net_ProcessICMPFrame(unsigned short *,unsigned short *,unsigned short,unsigned short *);

// fill TX-buffers
void net_PrepareARP_REQUEST(int);
void net_PrepareARP_ANSWER(unsigned short *,unsigned short *,unsigned short *);
void net_PrepareICMP_ECHO_REPLY(unsigned short *,unsigned short *,unsigned short,unsigned short *);
void PrepareTCP_FRAME(int,unsigned short TCPCode);
void net_PrepareTCP_DATA_FRAME(int,unsigned short);
void net_ProcessTCPFrame(unsigned short *,unsigned short *,unsigned short,unsigned short *);
void net_PrepareUDP_FRAME(int,unsigned short);
void net_ProcessUDPFrame(unsigned short *,unsigned short *,unsigned short,unsigned short *);

// general help functions
//void SendFrame(unsigned char send_mode);

void TCPStartRetryTimer(int);
void TCPStartTimeWaitTimer(int);
void TCPRestartTimer(int);
void TCPStopTimer(int);
void TCPHandleRetransmission(int);
void TCPHandleTimeout(int);
unsigned short CalcChecksum(void *Start, unsigned short Count, unsigned char IsTCP,unsigned short *rip,unsigned short *rMyIP);

// functions to work with big-endian numbers
unsigned short SwapBytes(unsigned short Data);
void WriteWBE(unsigned char *Add, unsigned short Data);
void WriteDWBE(unsigned char *Add, unsigned long Data);

// API functions
//void TCPLowLevelInit(void);                      // setup timer, LAN-controller, flags...
void TCPPassiveOpen(int);                       // listen for a connection
void TCPActiveOpen(int);                        // open connection
void TCPClose(int);                             // close connection
void TCPReleaseRxBuffer(int);                   // indicate to discard rec'd packet
void TCPTransmitTxBuffer(int,int);              // initiate transfer after TxBuffer is filled
void TCPClockHandler(void) __irq;               // Keil: interrupt service routine for timer 0
void TCP_ClockHandler(void);

//SocketStatus;
#define SOCK_ACTIVE                    0x01      // state machine NOT closed
#define SOCK_CONNECTED                 0x02      // user may send & receive data
#define SOCK_DATA_AVAILABLE            0x04      // new data available
#define SOCK_TX_BUF_RELEASED           0x08      // user may fill buffer

#define SOCK_ERROR_MASK                0xF0      // bit-mask to check for errors
#define SOCK_ERR_OK                    0x00      // no error
#define SOCK_ERR_ARP_TIMEOUT           0x10      // timeout waiting for an ARP-REPLY
#define SOCK_ERR_TCP_TIMEOUT           0x20      // timeout waiting for an ACK
#define SOCK_ERR_CONN_RESET            0x30      // connection was reset by the other TCP
#define SOCK_ERR_REMOTE                0x40      // remote TCP caused fatal error
#define SOCK_ERR_ETHERNET              0x50      // network interface error (timeout)

#endif
